The monitoring software tool, called DAI (Data Analysis and Interpretation) is developed upon request of the EURATOM inspectorate. This monitoring tool does more than just supervision: it interprets the signals and verifies the consistency and coherency with predefined criteria and without intervening in the process. These criteria are based on the design characteristics of the recipients and transfer mechanism.
In the case of the solution process in a reprocessing plant, the signals are visualizing the solution properties (temperature, density) and tank levels. The change in tank level of the feeding tank is cross-checked against the corresponding change in tank level of the communicating process tank and the software verifies the coherency in total mass transferred. In particular the start of a transfer has to be recognized appropriately and that with the appropriate signal profile, that differs for siphon transfer and mechanical pumping.
In order to ensure that no nuclear material is diverted, a complete accountancy system is imposed that combines verifications with high accuracy of low frequency (in general annually), with those of high frequency but with lower accuracy. Mainly the latter one, also known under near-real time accountancy, enhances the quality of executing the procedures, because it allows the inspector to localize in time a leakage problem to the operators.
The monitoring tool DAI has been completely successfully validated at the Reprocessing plant of La Hague (UP2 and UP3) and is now in use by the inspectors. Also the IAEA has selected this DAI software tool to monitor the Tokai reprocessing plant in Japan.